There are several types of microphones and related transducers, such as for example, dynamic, crystal, condenser/capacitor (externally biased and electret), etc., which can be designed with various polar response patterns (cardioid, supercardioid, omnidirectional, etc.). Each type of microphone has its advantages and disadvantages depending on the application.
One advantage of dynamic microphones (including moving coil microphones) is that they are passive devices and therefore, do not require active circuitry, external power, or batteries to operate. Also, dynamic microphones are generally robust or sturdy, relatively inexpensive, and less prone to moisture/humidity issues, and they exhibit a potentially high gain before causing audio feedback problems. These attributes make dynamic microphones ideal for on-stage use and better suited to handle high sound pressure, such as, for example, from close-up vocals, certain musical instruments (e.g., kick drums and other percussion instruments), and amplifiers (e.g., guitar amplifiers).
However, dynamic microphone capsules are typically larger than, for example, condenser microphones. This is because dynamic microphones typically employ a large acoustical compliance, or a large internal cavity C1 behind the diaphragm. The larger cavity tends to increase an overall axial length of the dynamic transducer, which increases the overall capsule size and limits the available form factors and practical applications of the microphone.
Accordingly, there is a need for a dynamic type microphone transducer that, among other things, provides improved form factors without sacrificing professional level dynamic microphone performance.